Either Democrat would beat any of the Republicans in the November general election, the polls shows. The tightest race would be between Lamont and Foley. The poll shows Lamont leading Foley 46 percent to 33 percent.

"In just three weeks, Fedele has cut Foley's lead from 35 points to 15 points," Quinnipiac University Poll Director Douglas Schwartz said in a statement. "Foley's negatives have risen, probably due in part to Fedele's TV ads.

"There is still a lot of voter uncertainty in this race, but with less than a week to go, there isn't much time left for Fedele," Schwartz said.

Twenty-one percent of likely GOP voters remain undecided, and 62 percent of those who picked a candidate say they might change their minds before the primary.

The Republican candidates were expected to respond to the poll results later Thursday.

About 14 percent of likely Democratic voters are undecided and 43 percent who chose a candidate in the survey say they could change their minds.

In a statement Thursday, Malloy's campaign said voters know Malloy, the endorsed Democrat, has the best experience to be governor.

"They're moving away from Ned because they don't want a CEO to run this state like a business," the statement said. "Ned is pouring hundreds of thousands of dollars a day into this race -- about $8 million so far -- and people are beginning to reject it."

"Connecticut voters still know that Ned Lamont has the best experience to create jobs and help their families," Lamont's statement said.

The poll of nearly 1,299 Connecticut registered voters was conducted July 28 to Aug. 2 and has an overall margin of sampling error of plus or minus 2.7 percentage points. The separate surveys of likely Democratic and Republican primary voters both have margins of sampling error of 3.1 percentage points.